INFO: task syz-executor.0:5138 blocked for more than 143 seconds. Not tainted 6.2.0-rc2-syzkaller-00127-g69b41ac87e4a #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:20920 pid:5138 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x9d1/0xe40 kernel/sched/core.c:6555 schedule+0xcb/0x190 kernel/sched/core.c:6631 wb_wait_for_completion+0x165/0x290 fs/fs-writeback.c:192 sync_inodes_sb+0x298/0xaa0 fs/fs-writeback.c:2725 sync_filesystem+0x16b/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x310 fs/super.c:474 kill_block_super+0x79/0xd0 fs/super.c:1386 deactivate_locked_super+0xa7/0xf0 fs/super.c:332 cleanup_mnt+0x494/0x520 fs/namespace.c:1291 task_work_run+0x243/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x134/0x160 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xad/0x110 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x2e/0x60 kernel/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x466c67 RSP: 002b:00007ffd9dc3a528 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000466c67 RDX: 00007ffd9dc3a5f9 RSI: 0000000000000002 RDI: 00007ffd9dc3a5f0 RBP: 00007ffd9dc3a5f0 R08: 00000000ffffffff R09: 00007ffd9dc3a3c0 R10: 0000000002da2893 R11: 0000000000000246 R12: 00000000004ae4c5 R13: 00007ffd9dc3b6a0 R14: 0000000002da2810 R15: 0000000000000002 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d5239d0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d5241d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/28: #0: ffffffff8d523800 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/u4:6/3218: #0: ffff88814529c938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262 #1: ffffc9000d367d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264 2 locks held by getty/4732: #0: ffff8880282cb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900015b02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6e8/0x1e50 drivers/tty/n_tty.c:2177 2 locks held by syz-executor.0/5138: #0: ffff88807b9820e0 (&type->s_umount_key#48){+.+.}-{3:3}, at: deactivate_super+0x96/0xd0 fs/super.c:362 #1: ffff88801f1dc7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff88801f1dc7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x279/0xaa0 fs/fs-writeback.c:2723 1 lock held by segctord/5160: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.2.0-rc2-syzkaller-00127-g69b41ac87e4a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e3/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x19b/0x3e0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xcd5/0xd20 kernel/hung_task.c:377 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 9 Comm: kworker/u4:0 Not tainted 6.2.0-rc2-syzkaller-00127-g69b41ac87e4a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: bat_events batadv_nc_worker RIP: 0010:lock_is_held_type+0x128/0x190 kernel/locking/lockdep.c:5713 Code: 48 c7 c7 e0 aa 0d 8b e8 76 14 00 00 b8 ff ff ff ff 65 0f c1 05 49 af 3c 75 83 f8 01 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 04 24 00 02 00 00 75 46 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b RSP: 0018:ffffc900000e7938 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000002 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8b0daae0 RDI: ffffffff8b697880 RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1d6043e R10: fffffbfff1d6043e R11: 1ffffffff1d6043d R12: 0000000000000246 R13: ffff88813fee0000 R14: 00000000ffffffff R15: ffffffff8d523780 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c6112cdd90 CR3: 000000000d28e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x89/0x130 kernel/rcu/update.c:125 trace_lock_acquire+0x98/0x260 include/trace/events/lock.h:24 lock_acquire+0xa5/0x400 kernel/locking/lockdep.c:5639 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:325 rcu_read_lock include/linux/rcupdate.h:764 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xc8/0x5b0 net/batman-adv/network-coding.c:719 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308